Rolling mill



K. GRUBER ROLLING MILL Filed Jan. 27, 1928 3 Sheets-Sheet, l

b his Arromey;

K. GRUBER ROLLING MILL Dec. 9, 1930.

Filed Jar 27, 1928 3 Sheets-Sheet, 5

llllll IIIIIIIIIIII //vV/v r00: KARL Gnuasn 1 Ms Arrarneys Patented Dec. 9, 1930 UNITED STATES KARL GBUBEB, OF RHEYDT, GERMANY ROLLING MILL Application filed January '27, 1928, Serial No. 249,882, and in Germany June 14, 1927.

The invention relates to rolling mills and more particularly to rolling mills for enlarging and smoothing tubes by rolling the same over a mandrel.

An object of the invention isto provide a mandrel Connection which can be easily uncoupled for inserting the tube to be rolled into the machine. A further object is to provide means whereby the mandrel stem can be displaced longitudinally as required. Other objects will be apparent from a consideration of this specification.

In most rolling mills of the class described the mandrel stem is under compression when w the tube is being. rolled. This permits the use of only relatively short and strongly or tightly held mandrel stems. With longer stems movable mandrel guides or the like are required. It has been suggested that the mandrel stem be placed on the entering side of the rolls in order that it may be under tension. Installations of this type, however, have developed difiiculties in the manipulation of the mandrel stem particularly in the necessary uncoupling of the stem in order to place in position the tube to be rolled.

Apparatus arranged in accordance with the present invention avoids the defects of these previous machines, by means of the novel construction and arrangement of parts which will be described.

Constructions made in accordance with the present invention consist essentially of a rolling mill having the mandrel stem shifted by automatic means such as conveyer pulleys or some other mechanical means. As an example, the mandrel stem with the mandrel attached may be shifted in such'fashion that the mandrel stem can be brought from the entering side to the exit side of the rolls and back again to the entering side.

The invention also contemplates the provision of means for releasing the stem from 4 its coupling and for replacing it in the same without interrupting the rotation and relative position of the rolls.

The invention is illustrated by way ofexample in the accompanying drawings in which- Figure 1 is a plan view of one form of the invention,

Figure 1a is a plan view of this form of the lnvention showing the general arrangement of the rolling mill,

Fig. 2 is a plan view on an enlarged scale of the form illustrated in Figure 1, with slight modifications,

Fig. 3 is a plan view of a modified form of the invention, so Fig. 4 is' a plan view of the form illustrated in Fig. 3 with the parts in a different posi- Fig. 5 is a sectional view showing the coupling arrangement for the mandrel stem, 5 Fig. 6 is an elevation of the hand-wheel.

illustrated in Fig. 5, Fig. 7 is an elevation partly in section of the mandrel and mandrel stem connection,

Fig. 8 is a view on the line 8'8 of Fig. 7 looking to the right,

Fig. 9 is a detail of the mandrel stem end,

Fig. 10 is a view of Fig. 9 turned at an angle of 90,

Fig. 11 shows the part illustrated in Fig. 9 when viewed from the right,

Fig. 12 is a detail of the mandrel connection,

Fig. 13 shows angle of 90,

Fig. 14 is an end view of Fig. 12,

Fig. 15 is a further detail of another form of mandrel connection, the mandrel being shown in section, and

Fig. 16 is an end view of Fig. 15.

In the drawings a pair of rolls a are shown having on their entering side a mandrel stem 6 which is designed to be under tension when rolling is taking place. The mandrel stem held at the end furth'est from the mandrel by W Fig. 12 when viewed at an i a coupling 0. At the other end of the mandrel coupling bolts are mounted thereon.

stem, that is to say the end adjacent the rolls, a mandrel-d is fastened.

For moving the mandrel stem longitudinally conveyor pulleys 6 may be placed on the entering side adjacent the rolls (see Figs. 1 and 1a). These conveyor pulleys are designed to seize the mandrel stem 1) and move it in either direction. when they are set in motion by a motor 8. Where conveyor pulleys are used they are of course mounted in such fashion that they will normally be sufliciently separated to permit the free passage between them of the mandrel stem and the tube which is being rolled. When the conveyor pulleys are to be operated they are brought together for instance by hydraulic or pneumatic means t so as to grip the mandrel stem and are then rotated in the direction necessary to give the desired movement of the stem.

Instead of employing co'nveyor pulleys, the mandrel stem may be moved by fluid shifting means, that is to say, by pneumatic or hydraulic means. Where the stem is moved by pneumatic or hydraulic means the stem alone, without the mandrel, is moved back away from the rolls on their entering side, for such a distance that the tube to be rolled may be laid in position (see Fig. 3). The stem is then returned through the tube by means of fluid pressure and the mandrel head is coupled to the stem (see Fig. 4).

The rolling floor may be extended as far as desired uninterruptedly from the exit side of the rolls in the direction of rolling. The rolled tubes may therefore be made of any desired length.-

The mandrel stem coupling, Which holds the mandrel stem during the operation of rolling, is shown in longitudinal section and in front elevation in Figs. 5 and 6. The mandrel stem coupling may be fixed to the machine bed or it may be adjustable in any given installation. It comprises a head 0 upon which a hand-wheel f is rotatably mounted. Slots 9 in the hand-wheel are cut eccentrically to the hand-wheel axis and slide spring boxes A containing looking or The locking or coupling bolts are stressed toward the axis of the hand-wheel by the springs i. When the hand-wheel f is turned in the direction of the arrow Z (see Fig. 6) the spring boxes h with their locking bolts k are shifted outward. This causes the bolts 70 to release the mandrel stem 6, which has been held in the couplingby the bolts is under the action of the springs z, gripping the stem end in the groove Z. When the mandrel stem is released it can be backed away from the coupling by means of the conveyor pulleys e as already explained.

the hand-wheel f may be turned back in the direction of the arrow 2 (see F ig. 6) thereby returning the locking bolts 7:: to the locking position. Upon being run back by the conveyor pulleys until its end contacts with the coupling, the mandrel stem will become automatically attached to the coupling by the action of the coupling bolts is in thrusting outward against the springs 71 until the groove Z comes beneath them. The springs 71 then force the coupling bolts k into engagement with the slot Z, thus coupling the mandrel stem in place. The stem coupling may be actuated by me chanical means other than a hand-wheel, of course. i .1

Two methods of fastening the mandrel d to the mandrel stem 6 are illustrated in Figs. 7 to 14, and in Figs. 15 and 16. In the first example the mandrel head 03 is fastened to its stem 6 by a bolt m which has at one end a head n, and at the other end a T-shaped part 0 (see Figs. 12 and 14). The part 0 fits into the correspondingly shaped end 39 of the mandrel stem 32 (see Figs. 9, 10 and 11), where it is firmly held in its seat by a sleeve 9 that is pushed over the junction by the spring 8 (see igs. 7 and 8). The bolt m may be readily and quickly removed from the mandrel stem by slipping back the sleeve q and removing the bolt laterally. In the example illustrated in Figs. 15 and 16, the mandrel d is pushed over the reduced end of the mandrel stem 1) and is there held in place by a key 1" provided with the usual cotter pin.

Other methods of fastening the mandrel to the mandrel stem may of course be applied.

With the understanding that the invention is susceptible of embodiment in various modified forms, and that the examples given are submitted merely for purposes of illustration.

I claim: v

1. Apparatus for expanding and smoothingmetal tubes comprising a pair of rolls, .a mandrel cooperating with said pair of rolls, and a mandrel stem carrying said mandrel, in combination with means for displacing said mandrel stem longitudinally, readily attachable and detachable means for constraining an end of said mandrel stem at the entering side of said rolls, and readily attachable and detachable means for connecting said mandrel to the other end of said mandrel stem.

2. Apparatus for expanding and smoothing metal tubes comprising a pairof rolls, a mandrel cooperating with said pair of rolls, a mandrel stem on the entering side of said pair of rolls by which said mandrel is carried, a coupling securing said mandrel stem in place and means for releasing said mandrel stem' from said coupling, in combination with means for displacing said mandrel stem lcingitudinally without moving said cou- P EF- 3. Apparatus for expanding and smoothing metal tubes comprising a pair of rolls, a mandrel cooperating with said pair of rolls, and a mandrel stem on the entering side of said rolls carrying said mandrel in combination with means adapted by longitudinal shifting to move the mandrel stem from the entering side of the rolls to the exit side and back again. I

4. Apparatus for expanding and smoothing metal tubes comprising a pair of rolls, a mandrel cooperating with said pair of rolls, a mandrel stem on the entering side of said pair of rolls by which said mandrel is carried, a coupling securing said mandrel stem in place and means for'releasing said mandrel stem from said coupling, in combination with means for displacing the mandrel stem toward the exit' side of the rolls and returning the same to the coupling, substantially as described.

5. Apparatus for extending and smoothing metal tubes comprising a pair of rolls, a mandrel cooperating with said pair of'rolls, a mandrelstem on the entering side of said pair of rollsby which said mandrel is carried, a coupling securing said mandrel stem in place, and means for releasing said mandrel stem from said coupling, in combination with conveyor pulleys adapted to displace said mandrel stem longitudinally toward the rolls while a tube is being placed in position ready for rolling and to return said mandrel stem to said coupling when the tube is in position.

6. Apparatus for expanding and smoothing metal tubes comprising a pair of rolls, a mandrel cooperating with said pair of rolls, a mandrel stem on the entering side of said pair of rolls b which said mandrel is carried, and a rea ily attachable and detachable coupling securing said mandrel stem in place, in combination with means for displacing the mandrel stem toward the exit side of the rolls and returning the same to the coupling.

7. Apparatus for expanding and smoothing metal tubes comprising a pair of rolls, a mandrel cooperating with said pair of rolls, a mandrel stem on the entering side of said pair of rolls by which said mandrel is carried, and a coupling securing said mandrel stem in place in combination with means for displacing the mandrel stem toward the exit side of the rolls and returning the same to the and means for disenga 'ng said locking bolts substantially as described.

In testimony whereof I have signed my name to this specification.

KARL GRUTBER.

coupling, mechanical means for unlocking the mandrel stem from the coupling, and automatic means for relocking the mandrel stem to the coupling, substantially as described.

8. Apparatus for expanding and smoothing metal tubes comprising a pair of rolls, a mandrel cooperating with said pair of rolls, a mandrel stem on the entering side of said pair of rolls by which said mandrel is carried and a coupling securing said mandrel stem in 

